Saturn has nine moons, but some of them are relatively small bodies--the ninth, discovered photographically by Professor Pickering in 1899, being especially minute--and others are situated at great distances from the planet, and for these reasons, together with the fact that the sunlight is so feeble upon them that, surface for surface, they have only one ninetieth as much illumination as our moon receives, they can not make a very brilliant display in the Saturnian sky.

To astronomers on Saturn they would, of course, be intensely interesting because of their perturbations and particularly the effect of their attraction on the rings.
This brings us again to the consideration of those marvelous appendages, and to the statement of facts about them which we have not yet recalled.
If the reader will take a ball three inches in diameter to represent the globe of Saturn, and, out of the center of a circular piece of writing-paper seven inches in diameter, will cut a round hole three and three quarter inches across, and will then place the ball in the middle of the hole in the paper, he will have a very fair representation of the relative proportions of Saturn and its rings.

To represent the main gap or division in the rings he might draw, a little more than three eighths of an inch from the outer edge of the paper disk, a pencil line about a sixteenth of an inch broad.
Perhaps the most striking fact that becomes conspicuous in making such a model of the Saturnian system is the exceeding thinness of the rings as compared with their enormous extent.

They are about 170,000 miles across from outer edge to outer edge, and about 38,000 miles broad from outer edge to inner edge--including the gauze ring presently to be mentioned--yet their thickness probably does not surpass one hundred miles! In fact, the sheet of paper in our imaginary model is several times too thick to represent the true relative thickness of Saturn's rings.
Several narrow gaps in the rings have been detected from time to time, but there is only one such gap that is always clearly to be seen, the one already mentioned, situated about 10,000 miles from the outer edge and about 1,600 miles in width.

Inside of this gap the broadest and brightest ring appears, having a width of about 16,500 miles.